Cognomen Bouian (Буян 
, Буиан , Bouian 
) , in the world, is quite a rare family name. The last name Bouian is habitual in Belarus, where it is quite a rare surname, Ukraine, where it is a rare surname, and Kazakhstan. Not in comparison with a country's population, it is commonest in Eastern Europe, particularly Ukraine, Belarus, and Russia. Very seldom, Bouian is the forename as well as the last name.
| VARIANT | COUNTRY |
|---|---|
| Буян | Ukraine, Belarus, Kazakhstan, Russia, Georgia |
| Буиан | Russia |
| Bouian | United States, Philippines, Chile |